How is a female, the weaker of the species, the protector? The mother sparrow entertains the cat by hopping on the porch railing, her tail up. She hops, and struts. She chirps. Looks around. Chirps more. Hops more. As big and obvious as she can make herself, with her tail straight up, she attempts to be the target of his attention. Taunting and irritating the cat, who is now behind a glass door. She has made of herself a decoy. She is parading herself as bait to distract the predator.
My little, domesticated Tigger might never find the nest, but she has sensed the threat. Rather than dive-bombing the cat and pecking at him, she chooses the way of peaceful intervention. She will tease him away from her young, and thus, she is the most potent protector.
Tigger is safely inside, away from temptation. The real danger to him is that she might fly away, and he, without wings, pursue her from two stories up. He would not stay aloft. And so, I am his protector, and have removed him from instinctive pursuit. The mother sparrow is a temptation he might not have surmised. He would have no forethought for the outcome. His instincts cause him to charge a toy, a moving target. He would have plunged to injury, or death.
So, here we are. Two females, each protecting the ones under our guardianship. She, the sparrow; she her nested young. Me, the mother of a house cat; protecting my young one from temptation. No blows have been exchanged. No threats. Just intervention. I intervene for my cat. She intervenes for her innocent young. I intervene for my inexperienced cat. It is not a truce, but violence is prevented.
Females are the most potent protectors.